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  1. KrisBlueNZ

    help me quickly: diode curves question

    Thanks LvW. You are a valued member here.
  2. KrisBlueNZ

    Help Identifying a Diode

    It looks like a generic 1A silicon diode that could be replaced with a 1N4004 or similar. But show us the rest of the circuit.
  3. KrisBlueNZ

    Designing a Time Delayed Relay

    Cool :) These are my thoughts on tinned vs. untinned copper wire: Please!
  4. KrisBlueNZ

    new here, H-bridge frustrations...

    Right. That circuit is dangerous in that way, because the default state for the output transistors is for both of them to be ON. It's only when the drive signal is within about 1V of the positive or negative supply that one of them will turn OFF! That will happen when the drive transistor is...
  5. KrisBlueNZ

    Newbie transistor question

    It depends how much collector current will be flowing, and whether the transistor is used as a "saturated switch". If you're turning the collector current ON and OFF, then the transistor IS being used as a saturated switch. In this case, have a look at these resources: 1...
  6. KrisBlueNZ

    Designing a Time Delayed Relay

    The current should split roughly evenly because each wire will have roughly the same resistance. I was just being paranoid when I assumed that each wire would be rated for the maximum load. But I still think you should use the thickest feasible wire, if for no other reason than it will make the...
  7. KrisBlueNZ

    Newbie transistor question

    Hi there and welcome to Electronics Point :-) You're right, current can only flow in a closed circuit. When you connect the base of an NPN transitor to the positive supply (through a resistor, to limit the current), current flows in a circuit from the positive side of the power source, through...
  8. KrisBlueNZ

    new here, H-bridge frustrations...

    Right, the first diagram, with PNPs and NPNs with their collectors connected together, is a bad idea because of the cross-conduction, which will occur whenever the voltage at the collector of the driver transistor is between about (VCC - 1V) and (GND + 1V). That can be avoided by driving each of...
  9. KrisBlueNZ

    help me quickly: diode curves question

    LvW, you're right in this case. Hints didn't seem to be working. I don't like spoon-feeding users in the homework forum but sometimes they just don't seem to be able to think for themselves. And in such cases, even spoon-feeding them doesn't always enable them to answer their question! But in...
  10. KrisBlueNZ

    help me quickly: diode curves question

    Because there are two types of diodes: a 1N4001 and a 1N5819. The 1N5819 is a special type of diode. What type of diode is it?
  11. KrisBlueNZ

    How can the new Yamaha HH65 Hi-Hat Pedals be modified to work with the Yamaha DD-50?

    OK, that page says (emphasis mine): So they don't say it's compatible with all continuous controllers - not on that page, at least. If you can find technical information on at least one continuous hi-hat controller that does work with the DM Dock, I may be able to suggest something.
  12. KrisBlueNZ

    AC adapters

    That voltage is just a bit too high for standard DC-powered converters, and a bit too low for standard line-powered converters. Even universal input line-powered supplies need an absolute minimum of 70V AC which will produce about 100V DC after rectification. That's too close to comfort. If it...
  13. KrisBlueNZ

    How can the new Yamaha HH65 Hi-Hat Pedals be modified to work with the Yamaha DD-50?

    Model number? Link to data?
  14. KrisBlueNZ

    How can the new Yamaha HH65 Hi-Hat Pedals be modified to work with the Yamaha DD-50?

    What are you connecting the HH65 to?
  15. KrisBlueNZ

    help me quickly: diode curves question

    Have you Googled diode incremental resistance? Or diode dynamic resistance? The curve shows you the relationship between two quantities, for a diode. What are those quantities? How do you calculate resistance from those two quantities? To calculate the dynamic or incremental resistance at a...
  16. KrisBlueNZ

    help me quickly: diode curves question

    LvW, this is the homework forum. That means we don't give full answers; we encourage users to do their due Google diligence and only ask about specific details if they get stuck.
  17. KrisBlueNZ

    voice processor

    Here's the suggested application circuit from the data sheet. The design from electronicsproject.org looks very similar. Coincidence? LOL The only differences are: the trigger circuit: the electronicsproject.org design use a relay instead of a pushbutton to trigger playback; this could be...
  18. KrisBlueNZ

    24V 2A Variable Power Supply

    Yes you can do that, as well as adding a resistor across the output as previously discussed. Yes, and the best way to prevent damage is to reverse-connect a diode across the transistor's base-emitter junction, not to connect a diode in series with the base (that will reduce the maximum output...
  19. KrisBlueNZ

    AC adapters

    You said your electric bike uses DC, at 100V. What is the actual supply voltage range over which the headlight needs to operate properly? What is the actual supply voltage range that the headlight needs to withstand without damage?
  20. KrisBlueNZ

    Colour organ jameco kit build virtual ground question

    That's not a very good design. The virtual ground, which they have labeled "GNDDIGITAL" for some reason, is created by U2 in the box in the bottom left corner, but U2 isn't needed. Just use R27, R28 and C15, and connect the centre point straight to "GNDDIGITAL" without U2. This will work fine...
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